CORTICAL, ANTI-MIGRATION, FACET DOWEL FOR FUSION OF FACET JOINTS IN THE SPINE AND DEVICES FOR SETTING THE SAME IN PLACE

摘要

A novel allograft is provided for insertion into a prepared site between adjacent spinal facets. The allograft or facet dowel is typically comprised of three portions, a partially spherical body defining a spherical segment, a nose portion, and a tail portion, all aligned along a longitudinal axis. In addition, a set of instruments is provided for the excavation of an allograft placement site between the two facets. The set of instruments includes a T-spade drill which will, in conjunction with a normal drill, excavate a site for the emplacement of the allograft. A novel method of using the instruments and the allograft is also provided.

主权项

1. A drill for use in conjunction open spinal facet implant surgery wherein the facet implant comprises a substantially rigid spherical segment having a diameter Ds; a tail segment comprising a cylindrical shape joined at a first end and integral to the spherical segment and having a removed end, the tail segment having a longitudinal axis, a diameter Dt, and a length Lt; and a nose segment comprising a cylindrical shape and a removed end, the nose segment integral with the spherical segment at a near end and having a length Ln, a longitudinal axis coincident with the longitudinal axis of the tail segment, and a diameter Dn, the drill comprising:
a nose portion comprising a cylindrical shape; a tail portion comprising a cylindrical shape, wherein the diameters of the nose portion and the tail portion are approximately the same as the diameter of the nose segment of the facet implant; and a body portion having a thickness substantially less than the diameter of the nose portion, and having a width about the same as the diameter of the spherical segment of the facet implant.